Turn of ipa-ra in builtins test (PR91059)

The gcc.c-torture/execute/builtins/lib directory contains a reimplementation
of many C library string functions, which causes non-trivial register allocation
bugs with LTO and static linked libraries.  To fix this long-standing test
issue, turn off ipa-ra which avoids the register corruption across calls.  All
builtin torture tests now pass on aarch64-none-elf.  Committed as obvious.

    testsuite/
	PR testsuite/91059
	PR testsuite/78529
	* gcc.c-torture/execute/builtins/builtins.exp: Add -fno-ipa-ra.

From-SVN: r273238

gcc/testsuite/ChangeLog

+2019-07-08  Wilco Dijkstra  <wdijkstr@arm.com>
+
+	PR testsuite/91059
+	PR testsuite/78529
+	* gcc.c-torture/execute/builtins/builtins.exp: Add -fno-ipa-ra.
+
 2019-07-08  Robin Dapp  <rdapp@linux.ibm.com>
 
 	* gcc.target/s390/rotate-truncation-mask.c: New test.

gcc/testsuite/gcc.c-torture/execute/builtins/builtins.exp

@@ -37,7 +37,7 @@ load_lib c-torture.exp
 torture-init
 set-torture-options $C_TORTURE_OPTIONS {{}} $LTO_TORTURE_OPTIONS
 
-set additional_flags "-fno-tree-dse -fno-tree-loop-distribute-patterns -fno-tracer"
+set additional_flags "-fno-tree-dse -fno-tree-loop-distribute-patterns -fno-tracer -fno-ipa-ra"
 if [istarget "powerpc-*-darwin*"] {
    lappend additional_flags "-Wl,-multiply_defined,suppress"
 }